Out of Africa

Photo courtesy of Jonathan Whitworth
Jonathan Whitworth of Aberdeen, with two assistants, at the Agricultural Development Corporation’s Enchili farm in Kenya.

By BILL SCHAEFER

For Farm & Ranch

Whether you’re a potato pathologist in Idaho or halfway around the world in Kenya, there are some practices common to both countries.

That’s one of the lessons Jonathan Whitworth learned during his time in Kenya.

Whitworth, a research plant pathologist at Aberdeen’s USDA-Agricultural Research Service station, spent three weeks last June assisting Kenya’s Agricultural Development Corp., a state-run organization in Kenya established to conduct tests to improve Kenya’s seed potato quality.

His work was sponsored by the Citizens’ Network for Foreign Affairs, a nongovernmental organization based in Washington, D.C., and financed by the U.S. Agency for International Development.

Whitworth said potatoes are second only to maize in Kenya. More than 270,000 acres of potatoes are grown in the east African nation. According to the USDA’s National Agricultural Statistics Service, Idaho growers planted about 345,000 acres in 2012, the most recent year NASS produced figures.

His main body of work was spent at the Molo Seed Potato research complex, where he instructed Kenyans how to test seed lots for viruses, including potato virus Y.

Whitworth, lab manager Daniel Mibei and three assistants collected samples from three seed farms to test for PVY in Molo, located east of Lake Victoria in western Kenya.

“We took samples at the farms and brought them back to the lab so we had materials to practice on,” Whitworth said.

Only 5 percent of Kenya seed potatoes are certified, Whitworth said. Many potato growers use uncertified, farmer-to-farmer seed, resulting in poor potato production due to increased levels of PVY and other viruses in the uncertified seed lots.

Whitworth also worked with seed-farm managers and their assistants, encouraging them to become more proactive in removing diseased potatoes from the the field.

“We did hands-on training in the field,” Whitworth said. “We did what we do with seed potato farmers here. We teach how to rogue potatoes and find the diseased potatoes and dig them out. Because that’s the way seed growers — wherever they are — improve their seed lots.”

The Molo lab is similar to potato research labs found in the U.S., Whitworth said.

“The industry is to the point now that they’re pretty much set as we are. They start with a tissue culture plant just like you would anywhere in the U.S.,” he said. “That plant produces a minituber and then that minituber goes into the field the next year and produces the first field year. In Idaho, we call it the nuclear crop, the beginning seed generation.”

Whitworth was impressed by the aeroponics greenhouse at the Molo complex.

“They’ve got this new aeroponics greenhouse where there’s no soil involved,” Whitworth said. “They can go in and harvest the tubers off the plants without harvesting the plants. So they can get multiple harvests off a single plant and it’s high-quality seed.”

Whitworth said he saw no russet varieties in Kenya. Many of the varieties grown in Kenya were developed through the International Potato Center. These varieties were selected and then named in Kenya. They include the Kenya Mpya, Sherekea, Asante, Kenya Karibu and Tigoni.

Two Dutch potato varieties, the Robijn and Desiree, also are cultivated in the country.

Following three weeks at Molo, Whitworth traveled to Naivasha to attend the ninth triennial conference of the African Potato Association.

At the conference, Whitworth gave presentations on the U.S. certification system and how the states and the USDA’s Animal and Plant Health Inspection Service work together to control diseases in seed potatoes.

Today, Whitworth is doing long-distance work from Aberdeen with the Molo lab. He’s working on a plan to have field workers gather samples from their seed fields, as well as other commercial fields. They will send the samples to Whitworth for testing.

Once the results are in, Whitworth said, “They would be able to show how much PVY that their seed fields have versus what the commercial fields have.”

The four weeks in the African nation left Whitworth with a better appreciation of all the amenities Americans enjoy.

“We really take for granted a lot of the advantages that we have just in everyday living and in production on our farms,” Whitworth said.